A study by the National Institute of Standards and Technology and the U.S. Navy has found that commercial fiber-optic telecommunications networks might be used as a backup for GPS when it comes to the transmission of precision time signals.
NIST and the U.S. Naval Observatory have teamed up with CenturyLink and Microsemi to conduct an experiment to determine whether telecom networks could serve as GPS backup for time transfer, NIST said Thursday.
Researchers used CenturyLink’s fiber optic cables to link NIST’s time scales in Boulder, Colorado, to USNO’s time scales at Schriever Air Force Base.
NIST and USNO also deployed Microsemi’s timing signal receivers and transmission equipment and measured the differences between local and transmitted Coordinated Universal Time or UTC.
Experiments showed that fiber-optic telecom networks could transfer UTC with a stability level of within 100 nanoseconds.
Researchers also found that the use of various equipment to transmit timing signals resulted in unequal time transfer delays between the two locations, failing to meet the 1 microsecond accuracy level.
“The 100 nanosecond stability level is good enough to meet a new telecommunications standard,” said Marc Weiss, lead study author and a mathematical physicist at NIST.
“We’ll continue trying to meet the 1 microsecond accuracy level, which is needed by critical infrastructure such as the power industry,” Weiss added.
NIST and USNO started the experiments in April 2014 and agreed to extend the research project to January 2017.